Spectacle lens machining method and apparatus

ABSTRACT

The present invention makes it possible to perform machining that forms holes or grooves for the attachment of parts to the outer circumferential edge surfaces of lenses of various lens patterns, both accurately and with good reproducibility, by means of a simple operation. The spectacle lenses  100  are positioned so that the machining areas of the spectacle lenses  100  are maintained in a fixed positional relationship with the machining reference position of the machining apparatus  200  by using spectacle lens fastening devices  400  which can fasten the spectacle lenses  100  with attached spectacle lens holding jigs  110  in place, and adjust the positions of these spectacle lenses  100 , to cause specified positions on the spectacle lenses  100  to contact the reference surfaces of a positioning reference plate  300.

TECHNICAL FIELD

The present invention relates to a spectacle lens machining method andapparatus which form holes, notches, and grooves or the like used forthe attachment of parts to the outer circumferential end surfaces or thelike of a spectacle lens.

BACKGROUND ART

In recent years, rimless type spectacles (rimless spectacles) haveattracted attention because of the advantages offered by such spectaclesin terms of a broad field of vision, light weight and the like. Suchrimless type spectacles include a type in which the circumference of thelower part of each lens is supported by a nylon thread, known as the“Nylor” type, a type called the “two-point” or “three-piece” type inwhich screw holes are formed through the lenses, and the lenses arefastened in place by screws that are passed through these screw holes,and the so-called “PINFEEL” type, in which blind holes are formed in theedge surfaces of the lenses, and pin-form projecting parts of thespectacle lens holding members are inserted and fastened in these blindholes. Rimless spectacles of the various types described above haverespective special features. However, in the case of such spectacles, itis not always easy to achieve a design that sufficiently ensures a wideeffective field of vision, durability, esthetic appearance and areduction in weight, etc., for lenses of various thicknesses and variousmaterials. Furthermore, such spectacles are not always satisfactory fromthe standpoint of machining costs and the like.

In recent years, therefore, rimless spectacles of a type in whichcutouts or the like are formed in the edges of the spectacle lenses, andattachment members are attached by being inserted into these cutouts,have been proposed. For example known spectacles of this type includethe spectacles described in Japanese Patent No. 2997438 (Japanese PatentApplication Laid-Open No. H10-228000), the spectacles described inJapanese Utility Model Registration No. 2602605 (Japanese Utility ModelApplication Laid-Open No. H7-32620, and the spectacles described inJapanese Patent Application Laid-Open No. 2000-147435.

In the case of spectacle lenses, the magnification ordinarily variesfrom user to user, and the shape of the lenses also depends on the shapeof the frames selected by the user. Accordingly, the thickness and shapeof spectacle lenses generally show individual variations. Consequently,when lenses used in the rimless spectacles involved in theabovementioned proposals are machined by a machining apparatus withnumerical control or the like, it is necessary to perform complicatedpositioning machine on a case by case basis in accordance with the shapeand thickness of the lenses, so that the machining efficiency isconspicuously poor.

With the foregoing in view, it is an object of the present invention toprovide an spectacle lens machining method and apparatus which make itpossible to perform machining that forms holes or notches or grooves orthe like for the attachment of parts to the outer circumferential edgesurfaces of lenses of various lens patterns, both accurately and withgood reproducibility, by means of a simple operation.

DISCLOSURE OF THE INVENTION

The first means used as means for solving the abovementioned problemsconstitute a spectacle lens machining method for machining spectaclelenses using a machining apparatus after spectacle lens edging has beenperformed in which the abovementioned spectacle lenses are edged so thatthey conform to the spectacle frame shape, wherein the machining by theabovementioned machining apparatus is performed with the spectaclelenses fastened to spectacle lens fastening devices which are disposedin the vicinity of the machining position of the abovementionedmachining apparatus, the abovementioned spectacle lens fastening devicesbeing equipped with fastening parts that fasten the abovementionedspectacle lenses in a specified positional relationship, and theabovementioned spectacle lens fastening devices positioning theabovementioned spectacle lenses fastened to the abovementioned fasteningparts by adjusting the positions of the abovementioned spectacle lensesrelative to the abovementioned machining apparatus, and, as thefastening devices, are used those device said fastening parts of whichhave a structure in which the spectacle lenses are fastened to thefastening devices by fastening spectacle lens holding jigs which areattached to the machining reference positions of the spectacle lensesbeforehand as jigs for fastening the spectacle lenses to the edgingmachine during the abovementioned edging.

The second means comprise a spectacle lens machining method in which aspectacle lens of a specified shape is machined by means of a machiningapparatus, this method comprising a spectacle lens holding jigattachment step of attaching a spectacle lens holding jig to a specifiedposition on the abovementioned spectacle lens, a spectacle lensfastening step of fastening the abovementioned spectacle lens bymounting the abovementioned spectacle lens holding jig in a spectaclelens fastening device which is disposed in the vicinity of the machiningposition of the abovementioned machining apparatus, which fastens theabovementioned spectacle lens in a specified positional relationship asa result of the mounting of the abovementioned spectacle lens holdingjig, and which positions the abovementioned spectacle lens by adjustingthe position of the abovementioned spectacle lens fastening device, apositioning step of positioning the spectacle lens by adjusting theposition of the abovementioned spectacle lens fastening device so that aspecified position on the abovementioned spectacle lens is caused tocontact a specified position on a positioning reference plate which isdisposed in the vicinity of the abovementioned machining apparatus andwhich is constructed so that when a specified position on theabovementioned spectacle lens is caused to contact the abovementionedspecified position on this positioning reference plate, the machiningarea of the abovementioned spectacle lens is maintained in a fixedpositional relationship with a machining reference position of themachining apparatus, and a machining step of machining the spectaclelens (which has been positioned by the abovementioned positioning step)by means of the abovementioned machining apparatus.

The third means comprise the spectacle lens machining method of thesecond means, wherein a spectacle lens holding jig which is attached tothe machining reference position on the spectacle lens beforehand as ajig which is used to fasten the spectacle lens to a lens edging machineprior to the edging of the spectacle lens in which the spectacle lens isedged so that the abovementioned spectacle lens conforms to the frameshape is used as the abovementioned spectacle lens holding jig, and theabovementioned spectacle lens holding jig attachment step is performedprior to the abovementioned spectacle lens edging.

The fourth means constitute the spectacle lens machining method of anyof the first through third means, wherein the abovementioned machiningapparatus that machines the spectacle lenses after said edging has beenperformed is a cutting machining apparatus which is controlled bynumerical control.

The fifth means constitute a spectacle lens machining apparatus formachining spectacle lenses after spectacle lens edging has beenperformed in which the abovementioned spectacle lenses are edged so thatthey conform to the spectacle frame shape, wherein the abovementionedspectacle lens machining apparatus has spectacle lens fastening deviceswhich are disposed in the vicinity of the machining position of theabovementioned machining apparatus, the abovementioned spectacle lensfastening devices being equipped with fastening parts that fasten theabovementioned spectacle lenses in a specified positional relationship,and the abovementioned spectacle lens fastening devices positioning theabovementioned spectacle lenses fastened to the abovementioned fasteningparts by adjusting the positions of the abovementioned spectacle lensesrelative to the abovementioned machining apparatus, and theabovementioned fastening parts have a structure in which the spectaclelenses are fastened to the fastening devices by fastening spectacle lensholding jigs which are attached to the machining reference positions ofthe spectacle lenses beforehand as jigs for fastening the spectaclelenses to the edging machine during the abovementioned edging.

The sixth means constitute a spectacle lens machining apparatuscomprising a machining apparatus which machines spectacle lenses,spectacle lens fastening devices which are disposed in the vicinity ofthe machining position of the abovementioned machining apparatus, thesespectacle lens fastening devices having fastening parts which fasten, ina specified positional relationship, spectacle lens holding jigs thatare attached to the machining reference positions of the spectaclelenses beforehand as jigs for fastening the spectacle lenses to theedging machine during the abovementioned edging, said spectacle lensfastening devices further fastening the abovementioned spectacle lensesin place by fastening the abovementioned spectacle lens holding jigs tothe abovementioned fastening parts, and said spectacle lens fasteningdevices further having position adjustment mechanism parts whichposition the abovementioned fastened spectacle lenses by adjusting thepositions of these lenses relative to the abovementioned machiningapparatus, and a positioning reference plate which is disposed in thevicinity of the machining position of the abovementioned machiningapparatus, this positioning reference plate having positioning contactparts which are constructed so that the machined parts of theabovementioned spectacle lenses are in a fixed positional relationshipwith the machining reference position of the abovementioned machiningapparatus when specified positions on the abovementioned spectaclelenses are caused to contact specified positions on the abovementionedpositioning reference plate, wherein positioning of the abovementionedspectacle lenses is accomplished by adjusting the positions of theabovementioned spectacle lenses by means of the abovementioned spectaclelens fastening devices so that specified positions on the abovementionedspectacle lenses are caused to contact specified positions on thepositioning contact parts of the abovementioned positioning referenceplate, and the abovementioned spectacle lenses are machined by theabovementioned machining apparatus.

In the abovementioned first and fifth means, the spectacle lens holdingjigs that are attached to the machining reference positions of thespectacle lenses beforehand as jigs for fastening the spectacle lensesto the edging machine during edging can be utilized “as is” and fastenedto the fastening devices; accordingly, the operation of fastening thespectacle lenses to the fastening devices can be performed simply andaccurately.

In the abovementioned second, third, and sixth means, a spectacle lensholding jig is attached to a specified position on the spectacle lens,this holding jig is fastened to a fastening device, and a specifiedposition on the spectacle lens is caused to contact a specified positionon a positioning reference plate. As a result, the spectacle lens can bepositioned so that the machining area of the spectacle lens is in afixed positional relationship with the machining reference position ofthe abovementioned machining apparatus. Consequently, the machining areaof the lens can be quickly and easily fastened in the machining positioneven if the thickness and shape of the lens vary.

In the abovementioned fourth means, cutting machining using numericalcontrol can be efficiently performed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart which illustrates the procedure of a spectaclelens machining method constituting one embodiment of the presentinvention;

FIG. 2 is a diagram which shows the construction of a spectacle lensmachining apparatus constituting one embodiment of the presentinvention;

FIG. 3 is an enlarged view of FIG. 2;

FIG. 4 is a diagram which shows the construction of the spectacle lensholding jig;

FIG. 5 is a diagram which shows an example of groove machining;

FIG. 6 is a diagram which shows an example of spectacles with end-piecesand bridge attached following groove machining; and

FIG. 7 is a diagram which shows the construction of a spectacle lensmachining apparatus constituting another embodiments of the presentinvention.

100 . . . spectacle lens; 200 . . . machining apparatus; 300 . . .positioning reference plate; 400 . . . spectacle lens fastening devices

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a flow chart which illustrates the procedure of a spectaclelens machining method constituting one embodiment of the presentinvention, FIG. 2 is a diagram which shows the construction of aspectacle lens machining apparatus constituting one embodiment of thepresent invention, FIG. 3 is an enlarged view of FIG. 2, FIG. 4 is adiagram which shows the construction of the spectacle lens holding jig,FIG. 5 is a diagram which shows an example of groove machining, and FIG.6 is a diagram which shows an example of spectacles with end-pieces andbridge attached following groove machining. Below, a spectacle lensmachining apparatus constituting one embodiment of the present inventionwill first be described, and a spectacle lens machining methodconstituting one embodiment of the present invention will then bedescribed, with reference to the abovementioned figures.

In FIG. 2, the spectacle lens machining apparatus constituting anembodiment of the present invention performs groove machining by meansof a cutting machining apparatus 200 with numerical control in the edgeportions of left and right spectacle lenses 100 that have been subjectedto edging. Specifically, machining is performed after the spectacle lens100 in question has been positioned and fastened by a positioningreference plate 300 and a fastening device 400 so that the machiningarea of the spectacle lens 100 is in a fixed positional relationshipwith the machining reference position of the machining apparatus 200,e.g., the position of a cutting blade 201.

The cutting machining apparatus 200 performs specified machining such asgroove machining, hole machining or the like while rotating the cuttingblade 201 in accordance with machining command signals from a computeror the like (not shown in the figures).

As is shown in FIG. 3, the positioning reference plate 300 is a metalblock whose cross-sectional shape is substantially trapezoidal. If thesurface facing toward the cutting blade 201 is taken as the uppersurface 301, then the positioning reference plate 300 has a lowersurface 302 that is substantially parallel to this upper surface, afront surface 303 (the back surface is not shown in the figures), andleft-right reference surfaces 305 and 306 which constitute the left andright surfaces of the positioning reference plate 300. The left-rightreference surfaces 305 and 306 are inclined surfaces (the angle ofinclination is 15 to 45° relative to the plane perpendicular to theupper and lower surfaces); these surfaces are used as surfaces thatregulate the position with respect to the left-right direction.Furthermore, vertical reference surfaces 307 and 308 that regulate theposition with respect to the vertical direction are disposed on thelower end portions of the left-right reference surfaces 305 and 306.

The vertical reference surfaces 307 and 308 are also inclined surfaces,and are respectively inclined by 10 to 30° with respect to the upper andlower surfaces 301 and 302. The positioning reference plate 300 isconstructed in such a manner that when the positions of the spectaclelenses 100 are determined so that specified positions on the spectaclelenses 100, e.g., the end surfaces of the machining areas, are caused tocontact the abovementioned left-right reference surfaces 305 and 306,and the respective edge parts (on one side) of the optical surfaces ofthe machining areas of the abovementioned spectacle lenses 100 arecaused to contact the vertical reference surfaces 307 and 308, thepositions of the machining areas of the abovementioned spectacle lenses100 are inevitably maintained in a specified positional relationshipwith the reference position of the cutting blade 201 of theabovementioned cutting machining apparatus 200.

A supporting shaft 310 is attached to the lower surface 302 of thepositioning reference plate 300. This supporting shaft 310 is attachedto a retraction mechanism part 320 so that the supporting shaft 310 canbe freely retracted, and this retraction mechanism part 320 is attachedto a forward-backward moving table 330. The abovementionedforward-backward moving table 330 is attached to a forward-backwardmoving mechanism part 340 so that the forward-backward moving table canfreely move forward and backward, and this forward-backward movingmechanism part 340 is fastened to a fastening table 350. Theforward-backward moving table 330 is arranged so that theforward-backward position of the positioning reference plate 300 can beaccurately adjusted to a designated position by turning and adjusting aforward-backward position adjustment knob 341.

The system is constructed so that when the system is set in the statefor the positioning operation, the positions of the abovementionedpositioning reference plate 300 in the vertical and left-rightdirections are inevitably maintained in a specified positionalrelationship with respect to the machining reference position of theabovementioned machining apparatus 200, and only the position in theforward-backward direction can be varied by the abovementionedforward-backward moving table 330. As will be described later, theforward-backward position of the forward-backward moving table 330 isdetermined from the pattern shape data of the spectacle lenses, lensedge thickness data, machining position data and the like; accordingly,this position is calculated by a computer which has a program fordetermining the position of the forward-backward moving table 330 fromthese values, and the position is set on the basis of this calculatedvalue by turning and adjusting the forward-backward position adjustmentknob 341. After the position of the positioning reference plate 300 hasthus been determined, the spectacle lenses 100 are positioned by causingthe end surfaces and the like of the spectacle lenses held in thespectacle lens fastening devices 400 to contact the abovementionedreference surfaces of the positioning reference plate 300.

Furthermore, when machining is to be performed, the abovementionedpositioning reference plate 300 is retracted by the retraction mechanismpart 320 to a position in which the positioning reference plate 300 doesnot interfere with the machining of the spectacle lenses 100 by thecutting blade 201. Specifically, the supporting shaft 310 is moved insuch a direction that the clamping pin 321 is guided by a guide groove322, so that the positioning reference plate 300 is positioned outsidethe region of the machining track of the cutting blade 201.

The spectacle lens fastening devices 400 determine the positions of thespectacle lenses 100 during machining, and fasten the spectacle lenses100 in place, by holding and adjusting the positions of the spectaclelenses 100 so that the edge surfaces or the like of these spectaclelenses 100 are caused to contact the reference surfaces of theabovementioned positioning reference plate 300.

Specifically, as is shown in FIG. 4., spectacle lens holding jigs 110are attached to specified positions on the spectacle lenses 100 prior toedging. The spectacle lens fastening devices 400 have spectacle lensmounting parts 410 which mount these spectacle lens holding jigs 110with the spectacle lens holding jigs 110 attached “as is”.

The spectacle lens mounting parts 410 have mounting holes 411, and mountthe spectacle lens holding jigs 110 inside these mounting holes 411 viarotation-checking fittings 412. Specifically, although this is notindicated in the figures, the rotation-checking fittings 412 areinserted into the mounting holes 411 in a fixed state with respect tothe direction of rotation. Furthermore, rotation-checking projections412 a are formed on the upper parts of these rotation-checking fittings412. Accordingly, when the spectacle lens holding jigs 110 are insertedinto the mounting holes 411, the spectacle lens holding jigs 110 aremounted inside the abovementioned mounting holes 411 in a state in whichthe abovementioned rotation-checking projections 412 a are inserted intobearing grooves 111 formed in the spectacle lens holding jigs 110. Inthis case, the spectacle lens holding jigs 110 are attached so that thecenters of the spectacle lens holding jigs 110 are positioned atspecified positions on the spectacle lenses 100, i.e., ordinarily in themachining centers, and the orientations of the bearing grooves 111 arealso fixed in specified directions; accordingly, in the state where thespectacle lenses are attached to the abovementioned mounting parts 410,if at least one position of each spectacle lens is specified, allpositions can be specified according to lens shape data or the like.

The spectacle lens mounting parts 410 are attached to verticaladjustment shafts 413, and these vertical adjustment shafts 413 areattached to bearing boxes 420 so that the vertical adjustment shafts 413are free to move in the vertical direction (i. e., in the direction ofthe Z axis). These bearing boxes 420 are attached to left-right movingmechanisms 430 so that the bearing boxes 420 are free to move in theleft-right direction (i.e., in the direction of the X axis), and theseleft-right moving mechanisms 430 are attached to a base 500. Lockingknobs 421 which lock the movement of the vertical adjustment shafts 413are disposed on the bearing boxes 420, and locking knobs 431 which lockthe left-right movement are disposed on the left-right moving mechanisms430. Furthermore, the abovementioned bearing boxes 420 are attached tothe left-right moving mechanisms 430 so that these bearing boxes 420 areinclined at a specified angle (0 to 30°) with respect to the verticaldirection. This attachment angle is desirable in order to set anappropriate value according to the base curve of the lenses. In thepresent embodiment, an example in which this attachment angle is fixedis described; if necessary, however, an angle adjustment mechanism maybe provided. Furthermore, fixed clamping bars 440 are attached to theabovementioned vertical adjustment shafts 413, and movable clamping bars441 are attached to these fixed clamping bars 440 so that the movableclamping bars 441 are free to move upward and downward. The tip ends ofthese movable clamping bars 441 are extended to points above theabovementioned spectacle lens mounting parts 410, and clamping heads 442are attached to the sides of the tip end portions of the movableclamping bars 441 that face the spectacle lens mounting parts 410. Twoguide poles 443 whose lower ends are fastened to the fixed clamping bars440 are passed through each of the movable clamping bars 441 so that themovable clamping bars 441 are free to move in the vertical direction.Furthermore, screw rods 444 which are screwed into the fixed clampingbars 440 at one end are fastened to the movable clamping bars 441 at theother end so that these screw rods 444 are free to rotate. Accordingly,the movable clamping bars 441 can be caused to move by rotating knobs445 formed on the end portions of the screw rods 444 at theabovementioned second ends of the screw rods 444, so that the clampingheads 442 are pressed against the spectacle lenses 100 mounted on thespectacle lens mounting parts 410, thus fastening the spectacle lenses100 in place.

In a state in which the abovementioned spectacle lens fastening devices400 have fastened the spectacle lenses 100 in place, the positions ofthese spectacle lenses 100 with respect to the direction of rotation(circumferential direction) and the positions of the spectacle lenseswith respect to the forward-backward direction (i.e., the direction ofthe Y axis) are definitively determined; however, the positions of thespectacle lenses 100 with respect to the vertical direction (thedirection of the Z axis) and the left-right direction (direction of theX axis) can be adjusted. These positions with respect to the verticaldirection (direction of the Z axis) and left-right direction (directionof the X axis) are determined by means of the positioning referenceplate 300.

Specifically, in a state in which the spectacle lenses 100 have beenfastened to the abovementioned spectacle lens fastening devices 400, thespectacle lenses 100 are positioned by moving the vertical adjustmentshafts 413 to which the spectacle lens mounting parts 410, fixedclamping bars 440 and movable clamping bars 441 are attached, and at thesame time moving the abovementioned vertical adjustment shafts 413together with the gear boxes 420 by means of the left-right adjustmentmechanisms 430, so that the end surfaces or the like of the spectaclelenses 100 are caused to contact the abovementioned respective referencesurfaces of the positioning reference plate 300. As a result, specifiedpositions on the spectacle lenses 100, e.g., the machining areas, aremaintained in a specified relationship with the machining referenceposition of the machining apparatus 200. Accordingly, specifiedmachining can be accomplished by sending specified machining commandsignals to the machining apparatus.

The example shown in FIG. 2 is an example in which the left and rightlenses are simultaneously positioned and the machining of end-pieceattachment grooves and bridge attachment grooves is performed.Specifically, as is shown in FIGS. 5 and 6, the term “end-pieceattachment grooves” refers to grooves 101 into which the end-pieces 150are inserted and fastened by bonding in the ear side end portions of thespectacle lenses 100 following edging. Furthermore, the term “bridgeattachment grooves” refers to grooves which are used for the insertionof both end portions of the bridge 160.

In this machining, the positioning reference plate 300 is retractedfollowing the abovementioned positioning, and (for example) the lens onthe left side in the figures is cut by the cutting blade 201 and thussubjected to groove machining for the attachment of the end-piece. Next,the cutting blade 201 is moved, and the lens on the right side ismachined. When this machining is completed, the left and right lensesare exchanged, and groove machining for the attachment of the bridge issimilarly performed. In this case, the machining data is sent from acomputer (not shown in the figures) as described above.

Next, a spectacle lens machining method constituting an embodiment ofthe present invention will be described with reference to FIG. 1. InFIG. 1, the term “lens” refers to an unworked round lens. The unworkedround lens that is selected in this case is a lens which has a specifiedmagnification and shape based on a prescription for the eyes of the useror other necessary prescription, and spectacle frame shape data or thelike.

Layout

First, a lens layout is performed as a prerequisite for the selection ofthe abovementioned round lenses. The term “lens layout” refer s to thedisposition of the position of the optical center in the edging shape(=lens pattern shape=geometrical shape) so that the centers of thepupils of the user will coincide with the optical centers of the lenseswhen the round lenses are edged in accordance with the frame shape andinserted into the frames, and these frames are donned by the use r ofthe spectacles. Specifically, because of differences between the shapeand size of the frames and the size of the face of the user, agreementbetween the positions of the pupils and the center positions of thegeometrical shapes of the frames (lens pattern shapes) is generallyrare. Accordingly, when the positions of the pupils are caused tocoincide with the geometrical centers of the lenses, these positionsdeviate from the optical centers, so that a disposition that correctsthis deviation is necessary. In other words, the amount of deviationbetween the geometrical centers and the optical centers in the lenspattern shapes is determined, and the geometrical centers are shifted byan amount corresponding to the amount of deviation from the opticalcenters of the round lenses, so that the geometrical centers arepositioned as the centers of the target shapes for edging.

Blocking

Next, blocking is performed on the basis of the results of theabovementioned layout. This blocking refers to the attachment of thespectacle lens holding jigs 110 (see FIG. 4), which are used to fastenthe lenses to the lens fastening shafts of the edging machine (whenedging is performed by this edging machine), to specified positions onthe spectacle lenses, e.g., the positions of the optical centers orgeometrical centers of the lenses.

The attachment is performed so that the spectacle lens holding jigs 110are firmly bonded to the spectacle lenses 100 by interposing a two-sidedtape that is as thin as possible between the spectacle lenses 100 andthe spectacle lens holding jigs 110. In this case, furthermore, sincethe spectacle lenses are cut while cutting water is applied to thelenses, it is necessary that the abovementioned two-sided tape have anample water resistance. Moreover, in order to avoid oscillation orshifting of the lens during lens cutting or lateral groove machining, itis advisable that the tape used have a thickness of 0.5 millimeters orless. Some other method may also be used to bond the spectacle lensholding jigs 110 to the spectacle lenses 100. The attachment surfacesmay be on either the convex sides or concave sides of the lenses.

Lens Pattern Cutting

The term “lens pattern cutting” refers to edging of the round lenses inconformity to the shape of the frames. The spectacle lens holding jigs110 attached to the abovementioned spectacle lenses 100 are attached tothe lens fastening shafts of the edging machine, and edging is performedby a method such as shape-following grinding or the like while thelenses are rotated.

Lens Clamping The spectacle lenses 100 in which edging has beencompleted are mounted on the abovementioned spectacle lens mountingparts 410 with the abovementioned spectacle lens holding jigs leftattached “as is”, and the movable clamping bars 441 are lowered so thatthe clamping heads 442 press against the spectacle lenses 100 and fastenthe spectacle lenses 100 in place. Furthermore, the method used tofasten the spectacle lenses 100 in place is not limited to theabovementioned embodiment; besides screw type clamping, it would also bepossible to use an air system, hydraulic pressure or an electric motorsystem.

Setting of Reference Plate (Bridge Side)

Once the spectacle lenses 100 have been fastened in place, thepositioning reference plate 300 is set. Specifically, theforward-backward position of the positioning reference plate 300 isaccurately adjusted to a designated position by turning and adjustingthe forward-backward position adjustment knob 341. This position variesaccording to the lens pattern and size; in the present embodiment, aworker loads the data of the operating instructions into a computer, sothat the set position is automatically displayed on the display of thecomputer. The worker then sets the positioning reference plate 300 inaccordance with this displayed value. Furthermore, instead of beingperformed manually, this adjustment could also be performed using anautomatic adjustment mechanism that is directly linked to the computer.

Positioning (Bridge Side)

Next, the abovementioned clamped spectacle lenses 100 are positioned bybeing caused to contact the reference surfaces of the abovementionedpositioning reference plate 300. The position of the positioningreference plate 300 is accurately taken as a reference point inthree-dimensional space by an NC machining machine, and programming isperformed so that the cutting blade 201 will move in accordance withrespective items using the position of this positioning reference plateas a reference. Accordingly, the machining of specified shapes can beperformed in specified positions on the lenses that have been set inaccordance with the positioning reference plate.

Furthermore, the abutting portions of the positioning reference plateare pointed so that these portions contact the lenses at single points.However, even if the lenses are slightly scratched by these pointedportions, the scratched portions are portions that are cut away by thecutting of the next process; accordingly, this causes no particularproblems. In the present embodiment, the reference surfaces 307 and 308of the positioning reference plate 300 recede at a angle ofapproximately 20 degrees with respect to the horizontal plane.Accordingly, for almost all of the lens curve of the convex shape ofeach lens, the lens edge and the reference surface make contact at asingle point.

Offsetting of Reference Plate

Once the abovementioned positioning has been completed, the positioningreference plate 300 is retracted to a region that is outside themachining track of the cutting blade 201. In the present embodiment,furthermore, a method was shown in which the positioning reference plate300 is fastened by being rotated to right angles after being pusheddownward. However, there are no particular limitations on the methodused. Any method may be used as long as the positioning reference plate300 can be shifted as a result to a position where the positioningreference plate 300 does not interfere with the cutting blade duringmachining.

Bridge Side NC Cutting

Next, using numerical control, the cutting blade 201 is moved by themachining apparatus 200 to a fixed position in the direction of the Zaxis from the contact position of the positioning reference plate 300,and cutting is performed for a fixed distance in the direction of the Xaxis. In the present embodiment, the cutting direction is set so thatthe cutting blade 201 is caused to move only in the direction of the Xaxis parallel to the datum line; however, there are no particularlimitations on the machining direction. Movement in a diagonal directionon the XY plane is possible, and movement according to a predeterminedshape (e.g., an oval shape) is also possible. Furthermore, movement inthe Z direction as well as on the XY plane is also possible. In thisway, grooves of various shapes can be formed in the lenses by means of asingle cutter.

In the present embodiment, the rotational speed of the cutting blade 201is set at 1,000 to 3,000 rpm. However, this speed varies according tothe type of glass being machined and the shape of the cutter used, andis not limited to any particular value. In order to prevent melting ofthe lenses caused by the heat of machining during cutting, it isdesirable to provide cooling based on air or cutting water.

Lens Unclamping

The clamping that fastens the lenses is loosened, and the lenses areremoved.

Exchange of Left and Right Lenses

The left and right lenses fastened to the lens fastening devices 400 areexchanged with each other. In this case, the lenses are set so that thevertical orientation is not changed.

Lens Clamping

The exchanged lenses are fastened in the same manner as described above.

Onsetting of Reference Plate

The retracted positioning reference plate 300 is returned to the setposition.

Setting of Position of Reference Plate (End-piece Side)

The positioning reference plate 300 is set in the position where theend-pieces are attached. The worker sets the position of the positioningreference plate 300 in accordance with the set value on the end-pieceside disposed by the display of the computer.

Positioning (End-piece Side)

The spectacle lenses are fastened in specified positions by causing thespectacle lenses 100 to contact the reference surfaces of thepositioning reference plate 300 in the same manner as described above.

Offsetting of Reference Plate

The positioning reference plate 300 is retracted in the same manner asdescribed above.

End-piece Side NC Cutting

The cutting blade 201 is move to a fixed position in the direction ofthe Z axis from the contact position of the positioning reference plate300 using numerical control in the same manner as described above, andcutting is performed for a fixed distance in the direction of the Xaxis.

Lens Removal

The clamping of the spectacle lenses 100 is loosened, and the lenses areremoved.

In the abovementioned embodiment, the positioning and fastening of thegroove machining jigs can be performed without removing the spectaclelens holding jigs fastened to the lenses in which lens edging has beencompleted, i.e., with these jigs fastened to the lenses “as is”. As aresult, groove machining for the purpose of forming grooves running intothe spectacle lenses from the edge surfaces of the lenses can beperformed accurately and with good reproducibility, and by means of asimple operation, for lenses with various types of lens patterns.Furthermore, the series of operations extending form the lens edging ofthe element lenses to the groove machining of the lenses can be mademore efficient.

FIG. 7 is a diagram which illustrates the construction of a spectaclelens machining apparatus constituting another embodiment of the presentinvention. The spectacle lens machining apparatus shown in FIG. 7 is anexample of an apparatus which is devised so that the spectacle lenses100 are held with the convex surface sides of the spectacle lensesfacing upward, and so that the cutting blade 201 performs cuttingmachining by contacting the abovementioned lenses from the convexsurface sides. Specifically, in the embodiment described previously, anexample was described in which the lenses 100 were held with the convexsurfaces of the lenses 100 facing downward, and machining was performedfrom the concave surface sides of the lenses. However, the embodimentdescribed below is an example of an apparatus which is devised so thatthe lenses 100 are held and machined with the surfaces of the lensesreversed from the case of the embodiment described above.

In this embodiment, since the lens surfaces are held in an attitude thatis the reverse of that in the abovementioned embodiment, the structureof the embodiment comprises parts that are the same and parts thatdiffer in terms of detailed structure but that have more or less thesame function. Accordingly, in the following description, parts of thestructure that are the same are labeled with the same symbols as in theabovementioned embodiment, and parts that differ in terms of detailedstructure but have the same function are labeled with symbols formed byadding 1000 to the numerical values of the symbols used in theabovementioned embodiment. Furthermore, descriptions that are thought tobe redundant are appropriately omitted.

In FIG. 7, the spectacle lens machining apparatus of the presentembodiment is used (for example) in a case where groove machining or thelike which has opening parts in the convex surface sides as indicated bythe dotted-line circles in FIG. 7 is performed by means of a numericallycontrolled cutting machining apparatus 200 in the edge parts of the leftand right spectacle lenses 100 that have been subjected to edging.

The positioning reference plate 1300 is attached to the supporting shaft310 in an attitude that is the reverse of that of the positioningreference plate 300 in the abovementioned embodiment (see FIGS. 2 and3); the remaining structures are identical to those of theabovementioned embodiment. Accordingly, in FIG. 7, the part thatcorresponds to the reference surface 307 of the abovementionedembodiment is the reference surface 1307, and in the figures, areference surface that corresponds to the reference surface 308 in theabovementioned embodiment is formed on the part that is contacted by theend surface of the corresponding lens 100. The portion of the lens 100that is machined is positioned by being caused to contact this referencesurface. Furthermore, the retraction mechanism part 320 to which thissupporting shaft 310 is attached, the forward-backward moving table 330,the forward-backward moving mechanism part 340, the fastening table 350and the like are the same as in the abovementioned embodiment.

Each of the spectacle lens fastening devices 1400 is constructed asfollows: specifically, a left-right moving mechanism 1430 is fastened toa base 500. A bearing box 1420 is fastened to this left-right movingmechanism 1430 by an L-shaped fitting used for attachment. A verticaladjustment shaft 1413 which is free to move in the vertical direction(i.e., in the direction of the Z axis) is attached to this bearing box1420. A locking knob 1421 which locks the movement of the verticaladjustment shaft 1413 is disposed on the bearing box 1420; furthermore,a locking knob 1431 which locks the movement in the left-right directionis disposed on the left-right movement mechanism 1430. Furthermore, theabovementioned bearing box 1420 is attached to the left-right movementmechanism 1430 so that this bearing box 1420 is inclined by a specifiedangle (0 to 300) relative to the vertical direction. It is desirablethat this attachment angle be set at an appropriate value in accordancewith base curve of the lenses. Accordingly, in the present embodiment,an example is described in which this attachment angle is fixed;however, it would also be possible to install an angle adjustmentmechanism if necessary.

Furthermore, a fixed clamping bar 1440 is attached to the abovementionedvertical adjustment shaft 1413 by means of a fastening fitting 1414, anda movable clamping bar 1441 is attached to this fixed clamping bar 1440so that this movable clamping bar 1441 is free to move in the verticaldirection. Specifically, two guide poles 1443 whose upper ends arefastened to the fixed clamping bar 1440 are passed through the movableclamping bar 1441, so that the movable clamping bar 1441 is free to movein the vertical direction. Furthermore, a screw rod 1444 which isscrewed into the movable clamping bar 1441 at one end is fastened to thefixed clamping bar 1440 at the other end so that this screw rod 1444 isfree to rotate, and the movable clamping bar 1441 can be moved upward ordownward by rotating a knob 1445 which is formed on the abovementionedsecond end of the screw rod 1444.

Furthermore, a spectacle lens mounting part 410 is mounted and fastenedto tip end portion of the fixed clamping bar 1440. Furthermore, aclamping head 1442 is fastened to the tip end of the movable clampingbar 1441. Accordingly, the movable clamping bar 1441 is moved byrotating the knob 1445 of the screw rod 1444, so that the clamping head1442 is pressed against the spectacle lens 100 mounted on the spectaclelens mounting part 410, thus fastening the spectacle lens 100 in place.

The abovementioned spectacle lens fastening device 1400 is devised sothat in a state in which the spectacle lens 100 is fastened in place,the position of this spectacle lens 100 in the direction of rotation(circumferential direction) and the position of the spectacle lens 100in the forward-backward direction (direction of the Y axis) aredefinitively determined. However, the position in the vertical direction(direction of the Z axis) and the position in the left-right direction(direction of the X axis) can be adjusted. The position in the verticaldirection (direction of the Z axis) and the position in the left-rightdirection (direction of the X axis) are determined by the positioningreference plate 1300. In the present embodiment, positioning can beaccomplished in a state in which the convex surface of each lens 100faces upward, so that machining of the type indicated by the dotted-linecircles in FIG. 7 can be accomplished with good efficiency.

Furthermore, in the embodiments described above, positioning wasaccomplished by causing specified positions on the spectacle lenses tocontact specified positions on the positioning reference plate; however,instead of using a positioning reference plate, it would also bepossible to use a contact type or a non-contact type position detectionmeans capable of detecting when specified positions on the spectaclelenses reach certain positions. For example, it would also be possibleto use position detection means having a position detection probe, andhaving a position detection probe which sends position informationconcerning the point of contact when a physical object contacts thisprobe. Alternatively, it would also be possible to use positiondetection means employing a detector that performs position detection ina non-contact manner using electromagnetic waves or the like instead ofsuch a contact type position detection probe.

INDUSTRIAL APPLICABILITY

In the present invention, as is clear from the above description,spectacle lenses are positioned so that the machining areas of thespectacle lenses are maintained in a fixed positional relationship withthe machining reference position of the machining apparatus by usingspectacle lens fastening devices which can fasten the spectacle lenseswith attached spectacle lens holding jigs in place, and adjust thepositions of these spectacle lenses, to cause specified positions on thespectacle lenses to contact the reference surfaces of a positioningreference plate. As a result, a spectacle lens machining method andapparatus which make it possible to perform machining that forms holesor grooves for the attachment of parts to the outer circumferential edgesurfaces of lenses of various lens patterns, both accurately and withgood reproducibility, and by means of a simple operation, are obtained.

What is claimed is:
 1. A spectacle lens machining method for machiningspectacle lenses using a machining apparatus after spectacle lens edginghas been performed in which said spectacle lenses are edged so that theyconform to the spectacle frame shape, wherein the machining by saidmachining apparatus is performed with the spectacle lenses fastened tospectacle lens fastening devices which are disposed in the vicinity ofthe machining position of said machining apparatus, said spectacle lensfastening devices being equipped with fastening parts that fasten saidspectacle lenses in a specified positional relationship, and saidspectacle lens fastening devices positioning said spectacle lensesfastened to said fastening parts by adjusting the positions of saidspectacle lenses relative to said machining apparatus, and, as thefastening devices, are used those devices said fastening parts of whichhave a structure in which the spectacle lenses are fastened to thefastening devices by fastening spectacle lens holding jigs which areattached to the machining reference positions of the spectacle lensesbeforehand as jigs for fastening the spectacle lenses to the edgingmachine during said edging.
 2. The spectacle lens machining methodaccording to claim 1, wherein said machining apparatus that machines thespectacle lenses after said edging has been performed is a cuttingmachining apparatus which is controlled by numerical control.
 3. Aspectacle lens machining method in which a spectacle lens of a specifiedshape is machined by means of a machining apparatus, said methodcomprising: a spectacle lens holding jig attachment step of attaching aspectacle lens holding jig to a specified position on said spectaclelens; a spectacle lens fastening step of fastening said spectacle lensby mounting said spectacle lens holding jig in a spectacle lensfastening device which is disposed in the vicinity of the machiningposition of said machining apparatus, which fastens said spectacle lensin a specified positional relationship as a result of the mounting ofsaid spectacle lens holding jig, and which positions said spectacle lensby adjusting the position of said spectacle lens fastening device; apositioning step of positioning the spectacle lens by adjusting theposition of said spectacle lens fastening device so that a specifiedposition on said spectacle lens is caused to contact a specifiedposition on a positioning reference plate which is disposed in thevicinity of said machining apparatus and which is constructed so thatwhen a specified position on said spectacle lens is caused to contactsaid specified position on this positioning reference plate, themachining area of said spectacle lens is maintained in a fixedpositional relationship with a machining reference position of themachining apparatus; and a machining step of machining the spectaclelens, which has been positioned by said positioning step, by means ofsaid machining apparatus.
 4. The spectacle lens machining methodaccording to claim 3, wherein a spectacle lens holding jig which isattached to the machining reference position on the spectacle lensbeforehand as a jig which is used to fasten the spectacle lens to a lensedging machine prior to the edging of the spectacle lens in which thespectacle lens is edged so that said spectacle lens conforms to theframe shape is used as said spectacle lens holding jig, and saidspectacle lens holding jig attachment step is performed prior to saidspectacle lens edging.
 5. The spectacle lens machining method accordingto claim 4, wherein said machining apparatus that machines the spectaclelenses after said edging has been performed is a cutting machiningapparatus which is controlled by numerical control.
 6. The spectaclelens machining method according to claim 3, wherein said machiningapparatus that machines the spectacle lenses after said edging has beenperformed is a cutting machining apparatus which is controlled bynumerical control.
 7. A spectacle lens machining apparatus for machiningspectacle lenses after spectacle lens edging has been performed in whichsaid spectacle lenses are edged so that they conform to the spectacleframe shape, wherein said spectacle lens machining apparatus hasspectacle lens fastening devices which are disposed in the vicinity ofthe machining position of said machining apparatus, said spectacle lensfastening devices being equipped with fastening parts that fasten saidspectacle lenses in a specified positional relationship, and saidspectacle lens fastening devices positioning said spectacle lensesfastened to said fastening parts by adjusting the positions of saidspectacle lenses relative to said machining apparatus, and saidfastening parts have a structure in which the spectacle lenses arefastened to the fastening devices by fastening spectacle lens holdingjigs which are attached to the machining reference positions of thespectacle lenses beforehand as jigs for fastening the spectacle lensesto the edging machine during said edging.
 8. A spectacle lens machiningapparatus comprising: a machining apparatus which machines spectaclelenses; spectacle lens fastening devices which are disposed in thevicinity of the machining position of the abovementioned machiningapparatus, these spectacle lens fastening devices having fastening partsto which spectacle lens holding jigs that are attached to the machiningreference positions of the spectacle lenses beforehand as jigs forfastening the spectacle lenses to the edging machine during theabovementioned edging are fastened in a specified positionalrelationship, said spectacle lens fastening devices further fasteningthe abovementioned spectacle lenses in place by fastening theabovementioned spectacle lens holding jigs to the abovementionedfastening parts, and said spectacle lens fastening devices furtherhaving position adjustment mechanism parts which position theabovementioned fastened spectacle lenses by adjusting the positions ofthese lenses relative to the abovementioned machining apparatus; and apositioning reference plate which is disposed in the vicinity of themachining position of the abovementioned machining apparatus, thispositioning reference plate having positioning contact parts which areconstructed so that the machined parts of the abovementioned spectaclelenses are in a fixed positional relationship with the machiningreference position of the abovementioned machining apparatus whenspecified positions on the abovementioned spectacle lenses are caused tocontact specified positions on the abovementioned positioning referenceplate, wherein positioning of the abovementioned spectacle lenses isaccomplished by adjusting the positions of the abovementioned spectaclelenses by means of the abovementioned spectacle lens fastening devicesso that specified positions on the abovementioned spectacle lenses arecaused to contact specified positions on the positioning contact partsof the abovementioned positioning reference plate, and theabovementioned spectacle lenses are machined by the abovementionedmachining apparatus.